Plesk 12.x / Linux :: Whitelisting Localhost And Mailing Lists

There seems to be confusion and documentation conflicts around whether we should be whitelisting localhost or not when using Mailing Lists.

In this documentation it suggests that localhost is no longer needed, and in fact needs to be removed from the whitelist if Outbound Spam protection is to function correctly: [URL] ....

But on the other hand, this documentation suggests to add localhost to the whitelists, even though the warning says otherwise, and that outgoing mailing list mail will still be processed by Outgoing Spam Control. [URL] ....

Through trial and error, i've found that my mailing lists were not able to send mail to external email accounts unless localhost is whitelisted.

If I want all mail scripts to be going through the Outbound Spam Control, and also having my mailing lists working, should I be adding localhost to my whitelist?